#include "string.h"

void reverse(int* str,int length)
{
  int* left = str;
  int* right = str + length  -1;
  int tmp;
  for(;left<right;++left,--right) {
    tmp = *left;
    *left = *right;
    *right = tmp;
  }
}

int main()
{
  int str[] = {1,2,3,4,5,6};
  reverse(str,6);

  return 0;
}
